Apache OpenSSL 4620:error:02001005:system library:fopen:Input/output error

In practice, the most common reason for this happening seems to be that the .rnd file in your home directory is owned by root rather than your account. The quick fix:

sudo rm ~/.rnd

For more information, here's the entry from the OpenSSL FAQ:

Sometimes the openssl command line utility does not abort with a "PRNG not seeded" error message, but complains that it is "unable to write 'random state'". This message refers to the default seeding file (see previous answer). A possible reason is that no default filename is known because neither RANDFILE nor HOME is set. (Versions up to 0.9.6 used file ".rnd" in the current directory in this case, but this has changed with 0.9.6a.)

So I would check RANDFILE, HOME, and permissions to write to those places in the filesystem.

If everything seems to be in order, you could try running with strace and see what exactly is going on.

On Windows you can also set the environment property OPENSSL_CONF. For example from the commandline you can type:

set OPENSSL_CONF=c:/libs/openssl-0.9.8k/openssl.cnf

to validate it you can type:

echo %OPENSSL_CONF%

You can also set it as part of the computer's environmental variables so all users and services have it available by default. See, for example, Environment variables in Windows NT and How To Manage Environment Variables in Windows XP.

Now you can run openssl commands without having to pass the config location parameter.